Design, Control, and Experiments of a Novel Robotic Uterine Manipulator With the Motorized 3-DoF Manipulation Rod

Abstract

To address the issue of declining performance over time with manual uterine manipulation during minimally invasive gynecologic surgery, we propose a novel uterine manipulation robot that consists of a 3-DoF remote center of motion (RCM) mechanism and a 3-DoF manipulation rod. This allows for tireless, stable, and safer manipulation in place of a human assistant. For the RCM mechanism, we propose a single-motor bilinear-guided mechanism that can achieve a wide range of pitch motion (-50 ∼ 34 degrees) while maintaining a compact structure. This novel uterine manipulation robot is equipped with a manipulation rod that has a tip diameter of only 6 mm, allowing it to accommodate almost any patient's cervix. The 30-degree distal pitch motion and ±45-degree distal roll motion of the instrument further improve uterine visualization. Additionally, the tip of the rod can be opened into a T-shape to minimize damage to the uterus. Laboratory experiments have shown the mechanical RCM accuracy of 0.373 mm and the maximum load of the distal pitch joint of 500 g. Feasibility has been demonstrated through ex-vivo and cadaver tests, as well as clinical trials.